Apparatus for charging a sweat furnace



March 19, 1963 F. F. DOWAT APPARATUS FOR CHARGING A SWEAT FURNACE 2 Sheets-Sheet 1 Filed NOV. 6, 1961 l I I I I ll 3,081,839 Patented Mar. 19, 1963 3,081,889 APPARATUS FOR CHARGING A SWEAT FURNAQE Frank F. Dowat, 1193i) Walker Road, Lemont, Ill. Filed Nov. 6, 1961, Ser. No. 150,346 4 Claims. (Cl. 21429) This invention relates to apparatus for charging furnaces, and particularly to apparatus for depositing a substantially uniform layer of particulate material into a furnace.

It is often necessary and desirable, in order to reclaim certain metals such as copper or aluminum, to melt off these metals from other higher melting point metals to which they have been bonded, attached or otherwise wedded. Generally such mixtures of metals are placed in a conventional furnace at a temperature just high enough to melt off the copper or aluminum, after which the remaining unmelted metals are mechanically removed from the furnace to prepare it for recharging.

Normally, the scrap mixed metal, such as iron-bearing aluminum, is shoveled manually or dumped in a haphazard manner onto the dry hearth of a furnace either through an open door in a side Wall or, in some instances, through the furnace roof. After the furnace has been charged, an operator rakes the material to spread it evenly over the entire hearth. This is necessary to permit uniform heating of the entire mass of metal, whereby the melting off of the aluminum is greatly facilitated. After the aluminum has been melted ofi the iron, the iron is raked out of the furnace to ready it for the next charge.

Considering, for example, the charging of a one-ton furnace, the charging operation of itself requires thirty minutes utilizing three laborers. During this thirty minute time interval, the furnace door must be open and consequently the furnace cools considerably from its approximately 1350 F. because of the entry of room temperature air. The furnace therefore must be brought up to the proper temperature before the aluminum will begin to melt. This reheating takes, on an average, about ten minutes. The average melting time for the aluminum in a one ton charge of material is approximately twenty minutes. The total number of charges which can thus behandled is about one per hour.

A further disadvantage of this prior art method is the rapid deterioration of the furnace caused by the repeated cooling and heating which is detrimental to the refractory linings of the hearth, walls and roof. The linings must be frequently rebuilt at some considerable cost, to say nothing of the losses due to the downtime of the furnace.

Prior art dumping devices have not proved to be satisfactory because, while they speeded up the actual loading of the material, it was still necessary to rake the material to spread it evenly over the hearth As a consequence, very little, if any, loading time was saved.

It is an object, therefore, of the present invention to provide a charging device which will quickly load a furnace while distributing the loaded material uniformly over the hearth.

A further object of the invention is to provide such a device whereby a furnace may be charged in such a short time that no appreciable cooling of the furnace can occur, whereby the life of the furnace lining will be substantially increased.

These and other objects and advantages will be. apparent from the following description and accompanying drawings wherein:

FIGURE 1 is a side elevational view of the preferred embodiment of the invention;

FIGURE 2 is an end elevational view of the device of FIGURE 1, but including the means for filling the open ended charging car, and

FIGURE 3 is a schematic diagram of the hydraulic piping arrangement for operating the charging device.

Referring to FIGURES 1 and 2 of the drawings, it is seen that the arrangement comprises a frame, indicated generally at 10* having spaced vertical members 12 and a plurality of upper and lower cross members, shown at 14 and 15 respectively. Suit-able cross bracing may be provided as required. Secured, preferably by welding, to the vertical members 12 are a pair of spaced rails 16, shown best in FIGURE 2 in the form of channels having their open ends facing each other and arranged to support a horizontally movable charger carriage indicated generally at 18.

The carriage 18 is formed of a pair of spaced, horizontally disposed angle or channel members: 20 to which are welded spaced axles 21 arranged to receive for rotation thereon car wheels 22. Wheels 22 are arranged to be received in rails 16 so that the carriage can move freely longitudinally of the frame 10. Preferably fixedly secured to the channel members 20 is a charging car 26 having side Walls 28 interconnected by a bottom wall 30. The charging car is open at its outer end, which is the end positioned to the right as viewed in FIGURE 1.

A hydraulic cylinder 32 is secured, preferably by a pivotal pin connection 34, to the frame 10 while an associated cylinder rod 36 is secured to the charging car at 38. The hydraulic cylinder 32 is arranged to move the charging car into and out of a conventional dry hearth furnace fragmentarily shown at 39 in FIGURE 1 and including a front wall 40' and a vertically movable door 42 defining a doorway 43 through which the charging car 26 may be moved into and out of the furnace as will be described hereinafter.

The rearward end of the charging car is provided with a movable end 44 which may be formed of a reinforced plate 45 having an outer perimeter conforming to the contour of the side and bottom walls of the car so as to be movable, as a pusher, through the car while remaining in close proximity with said walls. The movable end, or pusher, is supported by a guide rod 46 extending reawardly thereof and in turn slidably supported by a guide bracket comprising spaced upright members 48, bolted or otherwise secured to respective channel members 20, and a pair of vertically aligned cross members 49* to which are fastened vertical guides 49a. The cross members 49 and guides 4% may of themselves act as guides for rod 46 or, preferably, four rollers 50 positioned at right angles to each other may be utilized to supportably guide the reciprocal movement of the rod.

A second hydraulic cylinder 54 is pivotally mounted to a cylinder bracket 56 while the cylinder rod 58 is connected at 60 to the movable end 44 of car 26.

An arrangement for filling the charging car is shown in FIGURE 2 wherein a dumper 62 is mounted for pivotal movement in a frame 64. A dumping cylinder 66 having a rod 68 connected to pivot arm "70 is utilized to pivot the dumper 62 about pivot point '72 whereby the charging car may be filled with material to be charged into the 3 invention, and well within the skill of those familiar with this art.

To start the furnace charging operation, solenoid perated valve 76 is moved from the neutral position shown in FIGURE 3 toward the right whereupon pressure fluid is forced from the pump 86 through line 88 to the advance chamber of cylinder 66 whereby the rod 68 is advanced to dump a load of particulate material into the charging car 26. Valve 76 is then moved to its extreme left position while solenoid operated valve 78 is shifted to the right whereupon pressure fluid is forced through valve 76 and thence through line 90 to the return chamber of cylinder 66 to return the dumper to its original position. Simultaneously, pressure fluid is forced through line 92 into the advance chamber of hydraulic cylinder 32 Whereby the cylinder rod 36 is moved in advance stroke to force the charging car through the open door of the associated dry-hearth furnace. At the completion of this stroke, valve 76 is shifted to neutral position, valve 78 is shifted to its extreme left position and valve 80 is shifted to its right from the position shown in FIGURE 3. Pressure fluid is now forced through line 94 into the return chamber of cylinder 32 whereupon the charging car is moved'out of the furnace. However, simultaneously with this motion, the exhaust fluid of cylinder 32 is forced through line 92, valve 78, line 96, valve 80, line 98, and into the advance chamber of cylinder 54 whereby the rod 58 is moved on advance stroke at a rate predeterminately proportional to the return rate of rod 36. The particulate material which had been carried in the charging car 26 is therefore efiectively pushed out of the open end of the car as the car retracts, resulting in a uniform distribution of the material over the bed of the furnace. After the completion of the return stroke of rod 36 and the advance stroke of rod 38, valve 78 is shifted to neutral position and valve 80 is shifted to the extreme left position whereby the rod 58 is shifted to its starting position.

It is seen from the foregoing description that applicant has provided a simple inexpensive arrangement for uniformly loading particulate material into a dry-hearth furnace far more rapidly than has ever been accomplished. It will be apparent, however, that this invention need not be restricted to the charging of sweat furnaces but may also be utilized to charge scrap metal into open hearth furnaces. In such instances the charging time is shortened and melting of the added material is facilitated because of the spreading thereof across the width of the furnace. In fact, the device may be utilized wherever uniform, rapid loading of particulate material is contemplated.

I claim:

1. An arrangement for charging particulate material into a furnace comprising: a frame, a charging car for said material mounted on the frame for reciprocal movement relative thereto into and out of the furnace; pusher means mounted for movement with and also relative to said charging car and arranged for pushing said material out of an open end of the car and onto the floor of the furnace; and means for moving said car into said furnace and then retracting the car from the furnace while the pusher means is moved relatively of said car so that the particulate material is spread substantially uniformly over the floor of the furnace; said last mentioned means comprising a first hydraulic means for moving said car, a second hydraulic means for moving said pusher means, and other means for at times delivering hydraulic fluid from the exhaust side of said first hydraulic means to the intake side of said second hydraulic means so that the advance stroke of said second hydraulic means is controlled by the return stroke of said first hydraulic means.

2. An arrangement for loading particulate material into the bed of a furnace, comprising: a frame arranged for positioning adjacent the door of an associated furnace; a carriage reciprocal on said frame; a loading car for said material secured to the carriage for movement therewith, said car having an open end; a pusher member closing the other end of said car, said pusher member being movable relatively of the car; first hydraulic motor means having a cylinder fixed to the frame and a rod fixed to the carriage; second hydraulic motor having a cylinder secured to the carriage and a rod secured to said pusher member; means for supplying hydraulic fluid to one end of said first hydraulic cylinder for moving its rod on advance stroke to move the carriage into the furnace, and then supplying hydraulic fluid to the opposite end of said first hydraulic cylinder while accommodating flow of hydraulic fluid from said one end of said first hydraulic cylinder into said second hydraulic cylinder to advance said pusher member toward the open end of said car.

3. An arrangement for charging particulate material into a furnace comprising: a frame arrangement adjusted to be positioned adjacent the charging door of an associated furnace; spaced horizontally disposed rail members carried by the frame; a wheeled carriage carried on said rails for horizontal movement therealong; a loading car formed at one end of said carriage, said car having spaced side walls interconnected by a bottom wall and being open at the front end thereof; a pusher at the rear end of said car, said pusher being formed substantially to the contour of said walls; a first hydraulic cylinder secured to the frame and having advance and return chambers and a rod connected to the carriage; a second hydraulic cylinder pivotally secured to the carriage for movement therewith and having advance and return chambers and a piston rod connected to said pushena bracket secured to the carriage; a plurality of guide rollers mounted on said bracket and radially aligned about a common axis; a guide rod guidably received for movement relative thereto, one end of said guide rod being secured to said pusher; valve means arranged in one position thereof, for furnishing hydraulic fluid to the advance chamber of said first hydraulic cylinder; other valve means arranged, in one position thereof, for furnishing hydraulic fluid to the advance chamber of said second hydraulic cylinder; said first mentioned valve means being arranged, in another position thereof, to furnish hydraulic fluid from the advance chamber of said first hydraulic cylinder to the advance chamber of said second hydraulic cylinder whereby the movement of the carriage and the pusher are correlated.

4. An-arrangement for charging particulate material into a receptacle comprising: a frame, a carriage carried by a frame and arranged to be positioned adjacent an associated receptacle; a loading car at one end of said carriage; a pusher at the rear end of said car; a first hydraulic cylinder secured to the frame and having'a piston rod secured to the carriage; a second hydraulic cylinder secured to the carriage for movement therewith and having a rod secured to the pusher; first valve means arranged in one position thereof for furnishing hydraulic fluid to the advance chamber of said first hydraulic cylinder; second valve means arranged, in one position thereof, for furnishing hydraulic fluid to the advance chamber of said second hydraulic cylinder; said first valve means being arranged, in another position thereof, for furnishing hydraulic fluid to the return chamber of said first hydraulic cylinder, and simultaneously furnishing the exhaust fluid from the advance chamber of the first hydraulic cylinder to the advance chamber of the second hydraulic cylinder whereby the movement of the carriage and the pusher are correlated.

References Cited'in the file of this patent UNITED STATES PATENTS 

1. AN ARRANGEMENT FOR CHARGING PARTICULATE MATERIAL INTO A FURNACE COMPRISING: A FRAME, A CHARGING CAR FOR SAID MATERIAL MOUNTED ON THE FRAME FOR RECIPROCAL MOVEMENT RELATIVE THERETO INTO AND OUT OF THE FURNACE; PUSHER MEANS MOUNTED FOR MOVEMENT WITH AND ALSO RELATIVE TO SAID CHARGING CAR AND ARRANGED FOR PUSHING SAID MATERIAL OUT OF AN OPEN END OF THE CAR AND ONTO THE FLOOR OF THE FURNACE; AND MEANS FOR MOVING SAID CAR INTO SAID FURNACE AND THEN RETRACTING THE CAR FROM THE FURNACE WHILE THE PUSHER MEANS IS MOVED RELATIVELY OF SAID CAR SO THAT THE PARTICULATE MATERIAL IS SPREAD SUBSTANTIALLY UNIFORMLY OVER THE FLOOR OF THE FURNACE; SAID LAST MENTIONED MEANS COMPRISING A FIRST HYDRAULIC MEANS FOR MOVING SAID CAR, A SECOND HYDRAULIC MEANS FOR MOVING SAID PUSHER MEANS, AND OTHER MEANS FOR AT TIMES DELIVERING HYDRAULIC FLUID 